WO2006/026240 A1 discloses a processing device for coating a rudder unit of an aircraft. A graphic picture motif is automatically applied onto a surface that is already finish-painted in one color by means of robots. The rudder unit is held in the upright position by a support platform. A gantry robot is provided to both sides of the rudder unit, wherein the three movable spatial axes of said gantry robot move an applicator with a plurality of fluid nozzles for pigmented ink in accordance with a control in order to apply the desired motif. The thusly applied pigmented ink is permanently hardened on the aircraft paint by means of subsequent polymerizing.
According to the public state of the art, the above-described surface painting with an optimal application of a picture motif requires an activation of the surface to be painted, wherein this surface activation is, according to the state of the art, carried out manually in the form of various cleaning and sanding steps.
In such a conventional surface activation, the primed surface to be painted usually is initially pre-cleaned with a solvent. Subsequently, the already applied primer is manually processed with pneumatically operated random orbital sanders in order to achieve an evenly sanded surface. Subsequent cleaning with a solvent and a final dust binding with special dust binding cloths then need to be carried out.
The disadvantage of this conventional manual surface activation is the high expenditure of labor associated therewith. In this case, quite large surfaces with curved geometry need to be processed as precisely as possible. With respect to a rudder unit, in particular, the attached rudder and the installed rivets are obstructive during this processing. The front edge of the rudder is usually covered in the center position and can only be processed by turning the rudder sideward as it is also required for the manual sanding process. The upper edge of a rudder unit usually has a very significant curvature and therefore needs to be manually processed from above. The front edge and the base of a rudder unit also have a quite significant curvature that requires corresponding manual oscillating movements of the random orbital sander. The antistatic arresters that are usually arranged on the rudder unit should not be processed during the manual sanding because they cannot be painted.